Smoked-salmon Duchesses

Duchesses au Saumon Fumé (little choux pastries filled with smoked-salmon butter) teach one exact lesson: temperature is part of structure. The Choux must be dry and hollow, the salmon butter cold enough to hold yet supple enough to pipe, and the maigre jelly, a meatless fish aspic, cool enough to cling without melting what lies beneath. Get those temperatures right and each bite gives you delicate pastry, a rose-colored heart, and a clear, trembling glaze.

The original assumed a pastry section sending out trays of little Choux, a garde-manger with clarified maigre jelly already set, and fish stock never far from the fire. At home, you will bake one small batch, replace the naturally setting fish jelly with clear stock and measured fish gelatin, and use a food processor where the brigade used a mortar and tamis. I have changed the quantity and the staffing, not the intent: equal weights of smoked salmon and butter, hollow Choux, a clear fish glaze, and thorough chilling remain. The waiting trays were brigade scaffolding; the cold glaze over the filled pastry is the dish. One cook, one stove, one evening.

The moment that matters comes before glazing. Chill the filled Duchesses until firm, then bring the jelly to nappage, a light-coating consistency, no warmer than your fingertips. If it slides off, cool it briefly; if it turns ropy, warm it gently over barely warm water. Ça se rattrape.